ATLANTA, April 12 (UPI) -- There are no reported U.S. cases of H7N9 bird flu, but the Centers for Disease Control and Prevention are taking standard pandemic preparedness precautions.
Officials at the CDC said they received the first H7N9 virus isolate from China which will support this process.
The CDC began work on some preparedness measures based on the genetic sequences of the first three H7N9 viruses posted by China, the arrival of the actual isolate from China will allow this work to expand.
The virus isolate will be used to:
-- Continue to develop and evaluate a candidate vaccine virus against H7N9.
-- Further evaluate the CDC diagnostic test kit for detecting H7N9 infections in humans and make adjustments if needed.
-- Develop a serologic assay -- study characteristics of a disease using a blood sample -- to test for the presence of antibodies against the H7N9 virus in human blood samples. This will allow CDC to conduct studies to determine whether there is any pre-existing immune protection against this virus in the human population.
-- Grow the virus and share it within the World Health Organization's system with laboratories with proper U.S. Department of Agriculture permits and biosafety containment for preparedness activities.
-- Conduct additional testing to determine the susceptibility of the H7N9 virus to existing antiviral drugs.
Many of the human cases of H7N9 are reported to have had contact with poultry; but some cases reportedly have not had such contact, the CDC said. China is conducting follow-up investigations among close contacts of people infected with H7N9 to try to assess whether human-to-human spread of this virus is occurring.
These investigations suggest that there is no sustained -- ongoing -- spread of this virus from person-to-person at this time.
Human infections with avian influenza viruses are rare and most often occur after people are in contact with an infected bird. However, non-sustained person-to-person spread of other avian influenza viruses is thought to have occurred in the past, most notably with H5N1 viruses.